Machine for cutting bars



I Se t. 22, 1936.. J. 1.; ANDERSON 2,054,847

MACHINE FOR CUTTING BARS Filed May 1'7, 1955 4 Sheets-Sheet 1 INVENTOR A'rrnuz Sept. 22, 1936. J. L ANDERSON mcaims FOR CUTTING am Filed May 1'7, 1955 4 Shee ts-Sheet 2 2IENTOR ATTOR EY Sept. 22, 1936. J. L. ANDERSON 2,054,847

MACHINE FOR CUTTING BARS 4 Sheet--Sheet 3 Filed May 1'7, v19.35

INVENTOR )MZAIMW Sept.22, 1936. J. L. ANDERSON I MACHINE FOR GUTTi-NG BARS Filed May 1'7, 1935 4 Sheets-Sheet 4 J I 1. a 79 TI'ORNEY Patented Sept. I 22,, 1936 UNITED STATES mom son oo'r'rmo BARS James L. Anderson, Cluster, N. .L, assignor to Air Reduction Company, Incorporated, New York, N; Y., a corporation of New York Application May 17, 1935, Serial No. 22,013

14 Claims.

This invention relates to machines forcutting round bars or the like by means of a gas cutting :orch. a

Certain features of the invention relate to cut- ;ing machines of the type in which parallel crank irms support the torch and cause it to move parallel to itself while the tip follows an arc, the :enter of which lies on or close to the axis of the iar. I have found that it is important, in such nachines, in which the arms pass through posi- ;ions of dead center to prevent even small depar- ;ures of either arm from its parallel relation with be other arm, and it is an object of this invention provide an improved cutting machine of the :haracter indicated with means for preventing 0st motion between the parallel arms, and for )reventing toggle forces on the bearings.

When certain links of the torch-supporting tructure come into toggle relation they may cause excessive loads on some pivots of the linkage with esulting wear and lost motion. According to one eature of this invention power is applied to both If the shafts to which the parallel crank arms are onnected, so that each arm is moved by the orque of its connected shaft instead of being moved by the other arm through a connecting ink which has variable mechanical advantage hat may approach infinity in toggle positions of he parts.

The invention includes novel motion transmitlng connections between the shafts with means or preventing lost motion in the connections. he preferred embodiment of the inventioninludes'an electric motor for operating the mahine, but reference to power operated means" a the description and claims relates to mechaism operated by hand power as well as motor ower unless expressly limited to the latter.

Other features of the invention relate to motorperated bar cutting machines. The invention icludes a combination of automatic and manual ontrol switches for stopping the torch-supportig means at the end of a given are of movement, nd for shifting the motor circuits to cause the rotor to move the torch-supporting means in a averse direction when the motor is next started. motor governor on the high speed side of. reducon gearing maintains the speed of the torch uni- )rm. It may be said that another object of the mention is to provide an electric motor-operated, ar cutting machine with improved control means 'hich make the machine more satisfactory in peration and more convenient to use.

Another object of the invention is to provide bar cutting machine of the type having'parallel rank arms for moving the torch with improved arch-supporting means which can be set for outng bars of different radius without disconnecting ny of the pivots of the supporting linkage.

other objects, features and advantages of the invention will appear or be pointed out as the specification proceeds.

In the accompanying drawings, forming hereof: e

Fig. 1 is an end viewof a cutting machine embodying the invention;

part

Fig. 2. is a side elevation, partly broken away and partly in section, of the machine shown in Fig. 1;

Fig; 3 is a top plan view, partly in section, showing the machine of Figs. 1 and 2;

Fig. 4 is a detail sectional view showing a part of the driving mechanism of the machine illustrated in the preceding views: I

Fig. 5 is an enlarged detail view of the automatic' switch-operating mechanism; and

Fig. 6 is a wiring diagram showing circuits and.

control switches of the machine.

' A main frame I0 is fastened to a base I (Fig. 2) by screws |2. Supports l4 extend downward from the base for contact with the surface of a-bar IS. The faces of the supports M in contact with the bar are toothed, as shown in Fig. 1, and sloped like the jaws of a pipe vise for holding the base in set position on round bars of different diameter. A chain It holds the machine firmly against the bar l5. Both ends of the chain is are fastened to the base, one end through a swivel connection with a screw l8 (Fig. 2) which can be turned by a handle Hi to tighten the chain against the bar. The main frame l0 and base I l have handles 20 and 2| for use when moving the machine to a new location.

A torch 25 is clamped in a torch holder 26 having a link 21 pivotally connected by screws 28 and 29 to upper and lower bell-cranks 3| and 32, respectively.- The bell-cranks 3| and 32 are pivotally connected at their angles to upperanci lower crank arms 33 and 34, respectively, and the short arms of the bell-cranks are joined by a link 36. Split clamps 38 at the ends of the crank arms 33 and 34 fasten these arms securely to the shafts 40 and 4|, respectively. The arms 33 and 34 pass through their dead center positions when they cross a line passing through the axes of the shafts 40 and4l. dead center at the same time, the connecting link 36 will be compressed or tensioned, depending upon which of the arms is ahead of the other, with force of toggle magnitude, with the result that the bearings of the shafts 40 and 4| will be subjected to excessive loads and the other parts of the structure strained and possibly broken.

The positions of the bell-cranks 3| and 32 with respect tothe crank-arms 33 and 34 are fixed by a slotted link 43 which is pinned to the shaft 4| and is connected to the bell-crank 32 by a nut 44.

(Fig. 2) threaded on the end of the screw 29.

The arms and links described cause the torch 35 to move parallel to itself, so that it'always re- Unless both of the arms 33, 34 reach mains in a vertical position, while the torch tip moves along an are having a radius equal to the distance between the axes of the screw 29 and shaft 4 I. This distance can be changed by moving the screw 29 to different locations in the slot of the link 43. The screw '29 extends through a rider 46 which slides on the link 43. A scale on the link 43 indicates the radius of bar which the machine is set to cut when the edge of the rider 46 registers with the various divisions on the scale.

The torch and its supporting structure are shown in position to start a cut by full linesin Fig. l. The positions of the parts toward the end of the out are shown in dotted lines.

The shafts 49 and 4| turn in bearings in the main frame I0. Gears 48 and 49 are fastened to the shafts 40 and 4| and are driven in the same direction by a pinion 50 located between them. The pinion 50 is on a shaft 5| of a reduction gearing 52. The high speed shaft of the reduction gearing 52 is driven through gears 54 and another reduction unit 55 (Fig. 3) from a motor 56. This motor is of the governor-controlled type and has a knob 58 accessible from the outside of the machine for controlling the speed of the motor and the consequent speed of the torch.

Referring again to Fig. 2. there are drums 69 and GI extending from the sides of the gears 48 and 49, respectively. A metal ribbon 63 passes around the drums and is connectedwith the upper drum by a screw 64, shown in Fig. 4. There is a groove 65 in the drum and the screw 64 extends through a block 66 and the ribbon 63 and threads into a hole in the bottom of the groove. The block 66 fits the groove 65 and depresses the ribbon 63 into the groove to shorten the length of the ribbon and maintain it taut.

Turning the screw 64 to tighten the ribbon 63 tends to rotate the drums 68 and 6| and their connected gears 48 and 49 in opposite directions and causes teeth of these gears to contact with different sides of teeth on the driving pinion 5|]. For example, if the gear 48 is considered as in contact with the front of a tooth of pinion 58, then the gear 49 is in contact with the back face of a tooth of the pinion. There is, therefore, no lost motion in the gearing no matter how freely the gear teeth of the pinion may fit those on the ears.

Referring to Figs. 2 and 5, a switch trip 68 is secured on the shaft 40 by a set screw 69. This switch trip operates a double-throw snap-switch 78 which is fixed within the frame of the machine and has an operating lever with a ball end in the path of the switch trip 68.

The construction of the switch trip 68 is best shown in Fig. 5. The arms of the switch trip extend from opposite sides of its hub, but the angular limits through which the trip turns before operating the switch can be controlled by screws 73. These screws thread through the arms of the.switch trip in position to contact with the ball end of the lever l l, and the screws are held in any set position by lock nuts lll.

A pin 76 extends upward from the ball end of the lever H, and between collars lli on a rod 118 which extends through frame llll. There is a knob F9 on the outer end of the rod M3 for sliding the rod axially when an attendant wants to opswitches 10 and 8| are represented diagrammatically as pole switches in order to make the diagram clearer and more easily undertood. The switch 10 is the equivalent of a single pole, doublethrow switch, and the switch 8| is the equivalent of a double pole, double-throw switch. Both are snap switches and remain closed one way or the other. They never stop in open positions such as shown in Fig. 6, but they are shown open in order to illustrate the contacts and circuit relations more clearly.

The switches 10 and 8| are connected in series between the armature of the motor 56 and the field coil of the motor. The switch BI is connected in the circuit as a reversing switch. When the switches are in positions to close the circuit through the motor, operation of either switch will cut off the power and stop the motor. The motor can be started again by operating either switch, and it will rotate in the same direction as it was turning before it stopped, if started by operating the switch used to stop it, but the rotation will be in a reverse direction if started by the other switch.

The motor governor 8'! is connected in parallel with a resistor 88 which by-passes a portion of the current around the governor. The usual condenser 89 is connected across the governor to reduce arcing. i

In the operation of the machine the attendani ordinarily uses the switch 8| and lets the switch I! operate automatically as a limit switch to stor the machine at the end of a cut. Since the motel circuit is opened by the switch I8, the operatior of the switch 8| by the attendant to start the machine causes the mechanism to move in opposite directions for alternate cuts. This is convenience and effects considerable saving 0: time. After completing a cut through a bar, it i: not necessary to set the machine back to its start ing position because the tomb is in position tl start another cut in a reverse direction.

Various changes and modifications can b made in the illustrated embodiment of the inven tion, and some features can be used alone with out departing from the invention as defined ii the claims.

I claim:

1. In a machine for cutting round bars and th like, a torch-holder, a supporting arm rotatabl about a fixed axis, a link having pivot connec tions with the free end of said arm and with th torch-holder, releasable means for preventin; pivotal movement of the connections betweel the supporting arm and link when said arm anl link are set at various angles to one another t control the distance of the torch-holder from th center of rotation of-said arm, and means f0 causing the torch-holder to move parallel to it self during the operation of the machine.

2. Ina cutting machine having parallel cran arms for supporting a torch and for causing it t move parallel to itself through an arc of prede termined radius, links comprising a folding paral lelogram, pivot connections between two of th links of the folding parallelogram and the respec tive crank arms, a torch-holder connected wit one link of the parallelogram, and means hold ing said pivot connections against movement, bt releasable to permit the folding parallelogram t be shifted to control-the spacing of the torch holder from the crank armsl 3. In a machine for cutting round bars and th like, two parallel arms supported by shafts fc movement about relatively fixed axes, a bell-cran at the end of each arm, a pivot connection between each arm and one of the bell-cranks adjacent the angle of the bell-crank, links connecting corresponding ends of the bell-cranks to form a folding parallelogram, means for securing a torch to one 01' the connecting links, a radiuscontrolling link extending from one of the shafts to a point on one of the bell-cranks spaced from the connection of the bell-crank to its associated arm, and releasable clamping means for clamping the bell-crank to said radius-controlling link at various distances from the shaft for causing a torch secured to the connecting link of the parallelogram to move through arcs of different radii.

4.. In a cutting machine .of the -class havin spaced shafts, parallel crank arms on said shafts,. and a connecting link between said crank arms with means for supporting a torchfor movement parallel to itself through an arc while said crank arms move through angles extending on both sides of their dead-center positions in which the crank arms are in alinement, the combination with said crank arms and torch-supporting structure, of means connecting each crank arm with its shaft, and mechanism for applying power to both shafts to drive the two shafts positively and in unison. 5. In a machine of the character described, means for supporting a torch for movement par-, allel to itself including two parallel crank arms, shafts for rotating the crank arms-through various angular positions including dead-center positions in which one crank arm is nearest to the axis of rotation of the other, power driving mechanism connected with both shafts, and means for taking up any lost motion in the driving connections.

6. A machine for cutting metal bars and the like, comprising a torch-holder, means supporting the torch-holder for movement parallel to itself and along the arc of curvature of the metal bar, said means including two crank arms which move through dead-center positions during said movement of the torch-holder, connections between the crank arms for maintaining them in r parallel relation, and means for taking up any located between said gears and meshing with both of them, and mechanism for rotating the pinion.

8. A machine for cutting metal bars and the like, comprising a torch-holder, means supporting the torch-holder for movement parallel to itself and along the arc of curvature of the metal bar, said means including two crank arms, shafts connected to the crank arms, driving gearing for at least one of the shafts, a drum connected with each shaft, and a ribbon connecting said drums so that they turn together.

9. In a machine for cutting metal bars and the like, the combination-with a torch-holder and supporting means for causing a torch in the holder to occupy parallel positions as it follows the curvature of a metal bar, said means including parallel crank arms connected to spaced parallel shafts, of a gear and drum secured to each shaft, a pinion located between the gears and meshing with both-of said gears, mechanism for driving the pinion in either direction, a metal ribbon extending around both drums, and means for taking up slack in the ribbon to maintain it taut and take up any lost motion in the driving mechanism.

10. A machine for cutting metal bars and the like,'comprising a torch-holder and supporting means for causing a torch in the holder to occupy parallel positions as it follows the curvature of a metal bar, said means including spaced parallel shafts and parallel crank arms connected to the shafts, an electric motor, an adjustable, centrifugal governor for controlling the speed of the motor, and means for transmitting the motion of the motor to said parallel shafts, including speedreduction gearing driven by the motor and operatably connected with each of said shafts.

11. A bar cutting machine comprisingartorchholder, a supporting frame for the torch-holder including link means for causing a torch carried by the holder to move parallel toitself while its tip describes an are adjacent the surface of the bar, power mechanism for moving the torch-supporting frame including an electric motor, and switch means responsive to the movement of the frame for stopping the motor after the frame has moved a given distance corresponding to a predeterminedarc of movement of the torch tip.

12. A bar cutting machine comprising a torchholder, a supporting frame for the torch-holder including link means for causing a torch carried by the holder to move parallel to itself while its tip describes an are adjacent the surface of the bar, driving mechanism including. an electric motor for moving the frame and torch-holder, switch means for controlling the supply of electrol for said switch means, and a limit control,

responsive to movement of the torch-support ing frame, for operating the switch means when the frame reaches a given limit of movement.

13. In a bar cuttingmachine having mechanism for moving a cutting torch half-way around a bar while maintaining the positions of the torch parallel, an electric motor for driving said mechanism, a reversing switch for the motor, a double-throw snap-switch in the circuit of said reversing switch and connected so that operation of the reversing switch when the motor is running stops the motor and operation of said double-throw switch is necessary to start the motor running in the opposite direction.

14. In a bar cutting machine having mechanism for moving a cutting torch half-way around a bar while maintaining the positions of the torch parallel, an electric motor for driving said mechanism, two switch means both of which control the supply of electricity to the motor, said switch means being connected with the motor and with each other in such a manner that operated, but stopping of the motor by one switch and subsequent starting with the other switch reverses the direction of rotation.

JAMES L. ANDERSON. 

